nproc --version (return code: 0)
nproc (GNU coreutils) 8.25
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Giuseppe Scrivano.
nproc --help (return code: 0)
Usage: nproc [OPTION]...
Print the number of processing units available to the current process,
which may be less than the number of online processors
--all print the number of installed processors
--ignore=N if possible, exclude N processing units
--help display this help and exit
--version output version information and exit
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Full documentation at: <http://www.gnu.org/software/coreutils/nproc>
or available locally via: info '(coreutils) nproc invocation'